It is known for a known combine to be fitted with a header that comprises a reel for gathering the crop and a screw conveyor arranged behind the reel for pushing the crop towards the center of the header. From there the crop is transported by an elevator into machinery that threshes and separates the crop. The machinery may, for example, comprise one or more rotors arranged longitudinal or transversely but these need not be described herein in detail as the invention is only concerned with the header.
The reel of the header has a central shaft that is supported at its opposite ends on side arms of the header. An enclosed mechanism transmits drive to one end of the central shaft of the reel to rotate the reel about a transverse axis as the combine moves forward. Crop separators projecting forward of the reel form dividing lines in the growing crop to demarcate the swathe to be harvested in any one pass.
In use, the combine is steered in such a manner that the driven end of the rotor usually rides over a previously harvested swathe of land. Consequently, there is no crop still growing beyond that end of the reel. However, at its other end, the reel has crop growing all around it and this causes a problem because the crop tends to wrap itself around the central shaft and to become entangled in the gap between the end of the reel and the side arm of the header in which the shaft is supported. Aside from the fact that some of the crop is ruined, it is necessary to stop the combine periodically to remove the entangled crop to avoid excessive drag on the reel.
U.S. Pat. No. 4,199,927 addresses this problem by providing what is termed therein a weed shield. The shield includes a substantially flat panel member and a vertically oriented deflector plate attached along one longitudinal edge to the inwardly facing surface of the panel member. The weed shield includes means for attaching it to the reel support arm of the combine and is designed so as to cover a majority of the end of the reel and extend forward of the reel when the shield is attached to the support arm. The deflector plate is generally rectangular and its vertical length is substantially equal to the height of the panel member at the location of attachment of the plate to the panel member. The deflector plate is located forward of the forwardmost portion of the reel and is formed with a 135° bend such that it pivots away from the panel member at a 45° included angle. The deflector plate shields the corresponding hub portion of the reel on the end of the reel adjacent to where the weed shield is attached to the support arm.
The weed shield of U.S. Pat. No. 4,199,927 acts in effect as a crop separator with an additional deflector that pushes the crop away from the hub and into the path of the reel. While this may reduce the problem, it does not solve it entire because the crop has a tendency to spring back to its vertical position in the gap which is inevitably present between the deflector plate and the reel. Furthermore, a significant additional loading is placed on the ends of the reel as they have to harvest a crop has been bunched together and rendered more dense by the action of the deflector plate.